Although the recession contributed to what Siner called "supergrowth" over the last few years, she is not worried that the economic recovery will have a negative impact on sales. If anything, she said, it means customers will have more items to resell in the coming years.

"We've been through ups and downs in the economy for more than two decades, and no matter what happens, people like a bargain," she said. "Now that things are better, the people who gave us a try are committed customers."